AB1547 SHEAR-WAVE ELASTOGRAPHIC ULTRASOUND OF SECOND METACARPOPHALANGEAL IN SYNOVIUM OF RHEUMATOID ARTHRITIS
Authors: O. Sedano, J. Sedano
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Shear wave elastography (SWE) is a recent development in elastography ultrasound (SW-EUS). SWE allows quantitative evaluation of the elastic properties and stiffness of tissue and serves as an adjunct to conventional US techniques. There is a hypothesis that rheumatoid arthritis (RA) patients would have softer synovium than controls and this could be quantified with a slower SWV. We also assessed whether SWV varied with disease activity. The challenge in the application of SW-EUS to the synovium is that there are multiple bone tissue interfaces and fluid synovial interfaces in the joint which gave rise to increased chances of fallacious values. <h3>Objectives</h3> To perform a quantitative analysis of SW-EUS in second metacarpophalangeal (2MCP) synovium of RA patients and controls. Determine if there is a correlation between SW-EUS and disease activity. <h3>Methods</h3> A prospective case-control study. Fifteen patients with RA were consecutively recruited and matched with ten controls. Participants underwent clinical assessment, blood sampling, grey scale ultrasound (GSUS), power Doppler ultrasound and SW-EUS of MCP joints 2, on the dominant hand. Ultrasound examination was undertaken by two musculoskeletal trained sonographers. Both were blinded to patient diagnosis, clinical examination results, pathology and previous ultrasound findings. SW-EUS was performed first, followed by GSUS and PDUS. Scanning was carried out using ultrasound using linear array transducer at 6-18 mHz frequency and Virtual TouchTM software. MCP 2 of the dominant hand were scanned with joints resting at 20 degrees of flexion. The dorsal aspect of the joint was imaged in three planes; longitudinal midline (DLM), longitudinal radial (30° radial offset from midline, DLR) and longitudinal ulnar (30% ulnar offset from midline, DLU). <h3>Results</h3> Average age was 50. Mean RA disease activity (DAS28-ESR) was moderate at 3.85. Patients with RA (Figure 1) had lower mean SWV (5.27 m/s vs 12.00 m/s p&lt; 0.001) than controls (figure 2); had lower maximum synovial SWV than controls (6.88 m/s vs. 12.80 m/s P &lt;0.001). EM (RA 168.17 kPa, controls 437.81 kPa). RA low activity SWV (7.48 m/s); EM (168.17 kPa). high activity SWV (2.61 m/s); EM (25.45 kPa) Negative Pearson's correlation coefficients (PCC) were observed between mean SWV and disease activity markers including GSUS graded synovial thickness (PCC = -0.67, p = 0.03) and ESR (PCC = -0.45, p = 0.085). <h3>Conclusion</h3> This is the first pilot study in Latin America of SW-EUS in synovium. Mean SWV and elastic modulus was significantly lower in RA than controls. There was a negative correlation between mean and maximum SWV and GSUS synovial thickening and assessing disease activity in RA. Further study is warranted to confirm the role of SW-EUS in diagnosing and assessing disease activity in RA. <h3>References</h3> [1]Taljanovic MS, Gimber LH, Becker GW, Latt LD, Klauser AS, Melville DM, et al. Shear-wave elastography: basic physics and musculoskeletal applications. Radiographics. 2017; 37:855–870. [2]Chandel K, Prakash M, Sinha A, Sharma A, Chouhan DK, Sandhu MS. Role of Shear Wave Elastography of Synovium to Differentiate Rheumatoid and Tubercular Arthritis. J Med Ultrasound. 2021 Dec 27;30(1):30-35. doi: 10.4103/jmu.jmu_80_21. PMID: 35465588; PMCID: PMC9030352 <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.